Chapter 4
Introduction to
Valuation: The
Time Value of
Money
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McGraw-Hill/Irwin
Copyright © 2008 by The McGraw-Hill Companies, Inc. All rights reserved.
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Key Concepts and Skills
• Be able to compute the future value of
an investment made today
• Be able to compute the present value
of cash to be received at some future
date
• Be able to compute the return on an
investment
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Chapter Outline
• Future Value and Compounding
• Present Value and Discounting
• More on Present and Future Values
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Basic Definitions
• Present Value – earlier money on a time
line
• Future Value – later money on a time line
• Interest rate – “exchange rate” between
earlier money and later money
– Discount rate
– Cost of capital
– Opportunity cost of capital
– Required return
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Future Values
• Suppose you invest $1,000 for one year at
5% per year. What is the future value in one
year?
– Interest = $1,000(.05) = $50
– Value in one year = principal + interest =
$1,000 + 50 = $1,050
– Future Value (FV) = $1,000(1 + .05) = $1,050
• Suppose you leave the money in for another
year. How much will you have two years from
now?
 FV = $1,000(1.05)(1.05) = $1,000(1.05)2 =
$1,102.50
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Future Values: General Formula
• FV = PV(1 + r)t
– FV = future value
– PV = present value
– r = period interest rate, expressed as a
decimal
– T = number of periods
• Future value interest factor = (1 + r)t
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Effects of Compounding
• Simple interest (interest is earned only on
the original principal)
• Compound interest (interest is earned on
principal and on interest received)
• Consider the previous example
– FV with simple interest = $1,000 + 50 + 50 =
$1,100
– FV with compound interest = $1,102.50
– The extra $2.50 comes from the interest of
.05($50) = $2.50 earned on the first interest
payment
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Figure 4.1
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Figure 4.2
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Calculator Keys
• Texas Instruments BA-II Plus
– FV = future value
– PV = present value
– I/Y = period interest rate
• P/Y must equal 1 for the I/Y to be the period rate
• Interest is entered as a percent, not a decimal
– N = number of periods
– Remember to clear the registers (CLR TVM)
before (and after) each problem
– Other calculators are similar in format
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Future Values – Example 2
• Suppose you invest the $1,000 from the
previous example for 5 years. How much
would you have?
 FV = $1,000(1.05)5 = $1,276.28
• The effect of compounding is small for a
small number of periods, but increases as
the number of periods increases. (Simple
interest would have a future value of $1,250,
for a difference of $26.28.)
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Future Values – Example 3
• Suppose you had a relative deposit $10 at
5.5% interest 200 years ago. How much
would the investment be worth today?
– FV = $10(1.055)200 = $447,189.84
• What is the effect of compounding?
– Simple interest = $10 + $10(200)(.055) = $120
– Compounding added $447,069.84 to the value of
the investment
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Future Value as a General
Growth Formula
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4-12
• Suppose your company expects to
increase unit sales of widgets by 15%
per year for the next 5 years. If you
currently sell 3 million widgets in one
year, how many widgets do you expect
to sell during the fifth year?
 FV = 3,000,000(1.15)5 = 6,034,072
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Quick Quiz: Part 1
• What is the difference between simple
interest and compound interest?
• Suppose you have $500 to invest and
you believe that you can earn 8% per
year over the next 15 years.
– How much would you have at the end of
15 years using compound interest?
– How much would you have using simple
interest?
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Present Values
• How much do I have to invest today to have
some amount in the future?
 FV = PV(1 + r)t
 Rearrange to solve for PV = FV / (1 + r)t
• When we talk about discounting, we mean
finding the present value of some future
amount.
• When we talk about the “value” of
something, we are talking about the present
value unless we specifically indicate that we
want the future value.
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PV – One-Period Example
• Suppose you need $10,000 in one year for
the down payment on a new car. If you can
earn 7% annually, how much do you need to
invest today?
• PV = $10,000 / (1.07)1 = $9,345.79
• Calculator




1N
7 I/Y
10,000 FV
CPT PV = -9,345.79
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Present Values – Example 2
• You want to begin saving for your
daughter’s college education and you
estimate that she will need $150,000 in
17 years. If you feel confident that you
can earn 8% per year, how much do
you need to invest today?
 PV = $150,000 / (1.08)17 = $40,540.34
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Present Values – Example 3
 Your parents set up a trust fund for you
10 years ago that is now worth
$19,671.51. If the fund earned 7% per
year, how much did your parents
invest?
 PV = $19,671.51 / (1.07)10 = $10,000
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PV – Important Relationship I
• For a given interest rate – the longer
the time period, the lower the present
value (ceteris paribus: all else equal)
– What is the present value of $500 to be
received in 5 years? 10 years? The
discount rate is 10%
– 5 years: PV = $500 / (1.1)5 = $310.46
– 10 years: PV = $500 / (1.1)10 = $192.77
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PV – Important Relationship II
• For a given time period – the higher
the interest rate, the smaller the
present value (ceteris paribus)
– What is the present value of $500
received in 5 years if the interest rate is
10%? 15%?
• Rate = 10%: PV = $500 / (1.1)5 = $310.46
• Rate = 15%; PV = $500 / (1.15)5 = $248.59
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Figure 4.3
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Quick Quiz: Part 2
• What is the relationship between
present value and future value?
• Suppose you need $15,000 in 3 years.
If you can earn 6% annually, how much
do you need to invest today?
• If you could invest the money at 8%,
would you have to invest more or less
than at 6%? How much?
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The Basic PV Equation Refresher
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• PV = FV / (1 + r)t
• There are four parts to this equation
– PV, FV, r, and t
– If we know any three, we can solve for the
fourth
• If you are using a financial calculator, be
sure to remember the sign convention or
you will receive an error when solving for r
or t
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Discount Rate
• Often, we will want to know what the
implied interest rate is in an investment
• Rearrange the basic PV equation and
solve for r
 FV = PV(1 + r)t
 r = (FV / PV)1/t – 1
• If you are using formulas, you will want
to make use of both the yx and the 1/x
keys
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Discount Rate – Example 1
• You are looking at an investment that will pay
$1,200 in 5 years if you invest $1,000 today.
What is the implied rate of interest?
 r = ($1,200 / $1,000)1/5 – 1 = .03714 = 3.714%
 Calculator – the sign convention matters!!!
• N=5
• PV = -1,000 (you pay $1,000 today)
• FV = 1,200 (you receive $1,200 in 5 years)
• CPT I/Y = 3.714%
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Discount Rate – Example 2
• Suppose you are offered an investment
that will allow you to double your
money in 6 years. You have $10,000 to
invest. What is the implied rate of
interest?
 r = ($20,000 / $10,000)1/6 – 1 = .122462 =
12.25%
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Discount Rate – Example 3
• Suppose you have a 1-year old son
and you want to provide $75,000 in 17
years toward his college education. You
currently have $5,000 to invest. What
interest rate must you earn to have the
$75,000 when you need it?
 r = ($75,000 / $5,000)1/17 – 1 = .172686 =
17.27%
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Quick Quiz: Part 3
• What are some situations in which you
might want to compute the implied interest
rate?
• Suppose you are offered the following
investment choices:
– You can invest $500 today and receive $600 in
5 years. The investment is considered low risk.
– You can invest the $500 in a bank account
paying 4% annually.
– What is the implied interest rate for the first
choice and which investment should you
choose?
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Finding the Number of Periods
• Start with basic equation and solve for t
(remember your logs)
 FV = PV(1 + r)t
 t = ln(FV / PV) / ln(1 + r)
• You can use the financial keys on the
calculator as well. Just remember the
sign convention.
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Number of Periods – Example 1
• You want to purchase a new car and
you are willing to pay $20,000. If you
can invest at 10% per year and you
currently have $15,000, how long will it
be before you have enough money to
pay cash for the car?
 t = ln($20,000 / $15,000) / ln(1.1) = 3.02
years
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Number of Periods – Example 2
• Suppose you want to buy a new house.
You currently have $15,000 and you
figure you need to have a 10% down
payment plus an additional 5% in
closing costs. If the type of house you
want costs about $150,000 and you
can earn 7.5% per year, how long will it
be before you have enough money for
the down payment and closing costs?
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Example 2 Continued
• How much do you need to have in the future?
– Down payment = .1($150,000) = $15,000
– Closing costs = .05($150,000 – 15,000) = $6,750
– Total needed = $15,000 + 6,750 = $21,750
• Compute the number of periods
–
–
–
–
PV = -15,000
FV = 21,750
I/Y = 7.5
CPT N = 5.14 years
• Using the formula
– t = ln($21,750 / $15,000) / ln(1.075) = 5.14 years
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Example: Spreadsheet Strategies
• Use the following formulas for TVM
calculations
–
–
–
–
FV(rate,nper,pmt,pv)
PV(rate,nper,pmt,fv)
RATE(nper,pmt,pv,fv)
NPER(rate,pmt,pv,fv)
• The formula icon is very useful when you
can’t remember the exact formula
• Click on the Excel icon to open a
spreadsheet containing four different
examples.
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Example: Work the Web
• Many financial calculators are available
online
• Click on the web surfer to go to the
present value portion of the
Moneychimp web site and work the
following example:
– You need $40,000 in 15 years. If you can
earn 9.8% interest, how much do you need
to invest today?
– You should get $9,841
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Table 4.4
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Quick Quiz: Part 4
• When might you want to compute the
number of periods?
• Suppose you want to buy some new
furniture for your family room. You
currently have $500 and the furniture
you want costs $600. If you can earn
6%, how long will you have to wait if
you don’t add any additional money?
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Comprehensive Problem
• You have $10,000 to invest for five years.
• How much additional interest will you earn
if the investment provides a 5% annual
return, when compared to a 4.5% annual
return?
• How long will it take your $10,000 to
double in value if it earns 5% annually?
• What annual rate has been earned if
$1,000 grows into $4,000 in 20 years?
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